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FRIMEDBIO-Fri prosj.st. med.,helse,biol

Phanerozoic diversification: linking observation and process

Alternative title: Phanerozoisk diversifisering: fra observasjon til prosess

Awarded: NOK 9.3 mill.

The Earth is inhabited by a dazzling array of organisms. Some groups of organisms are much more species rich than others. For example, there are fewer than thirty species of crocodilians today but over ten thousand species of birds. The differences in current day species richness among diverse groups of organisms are the result of different rates of species generation and species extinction in both the distant and the recent past. To understand why groups of organisms, ranging from plankton, mollusks to mammals, are so different in their diversity, we turn to a very rich source of information, namely, the fossil record. The fossil record consists of the remains of organisms that have lived in the past. By teasing apart the complex processes of speciation, extinction and preservation that led to the making of the fossil record, we can distill evolutionary and ecological processes of the deep past. In our research, we (i) estimated the number of dinosaur species that have lived in the past; (ii) inferred that clams really did suppress the evolution of brachiopods over geological time scales, (iii) discovered that deep ocean temperatures influenced the global abundance of planktonic microorganisms through 65 million years, (iv) found out that interspecific competitive outcomes can be predicted by size, where ?bigger is better?. In the last year of our research program, we wrote about how to study causal mechanisms of evolutionary changes using information from the fossil record, and also how to better quantify the lack of change (in size and other quantitative traits) to understand evolutionary stasis among fossil species. We also built statistical tools that other scientists can use to dissect their own datasets.

The greatest outcome of this grant is that I secured a ERC-Consolidator Grant by using opportunities provided by the RCN to develop ideas and collect pilot data for the ERC-granted project. It resulted in my having a research group currently consisting of about 12 persons (including Master students). We have also used the opportunity to build an international collaborative network both to collect difficult-to-sample information and to increase statistical expertise in our own group. We have published many papers in highly respected journals within the fields of evolution, ecology and paleontology. This acknowledgement of our work probably also contributed to my being employed as an executive editor (1.5 years ago) at a top ecology/evolution journal with the British Ecological Society, thus highlighting Norway's contribution to the field. I have also been invited to be a CO-PI on internationally funded projects, probably because of the visibility our RCN funded work has gained.

Rates of evolution as manifested in diversity dynamics vary in time, space and among groups of organisms. Despite consensus that speciation/origination and extinction rates vary over the Phanerozoic, there is little agreement on the estimates of these rat es, nor processes behind their variation. This is because existing models do not adequately capture the processes that generated fossil data, from which inferences regarding diversification are made. The aim of LINK is to recover true evolutionary pattern s and processes from data filtered through and biased by incomplete sampling in the fossil record. By explicitly modeling both evolutionary processes as well as the imperfect observation of such processes, I will generate new, robust estimates of Phaneroz oic global diversification. Using these accurate estimates of diversification and measures of their uncertainty, I will then quantify the contributions of climate, autecological traits and other biological factors to variation in global diversification ra tes. Global dynamics result from individual-level dynamics. Hence, I propose to disassemble geographical trajectories of individual fossil taxa to understand meta-population dynamics and their contribution to global processes. Local drivers can likewise contribute to global processes. I propose to synthesize existing data of local climate variation and abundance dynamics of individual species in high-resolution time series from the biostratigraphic literature in a new database. Applying novel analyses to this new database, I will shed light on how local climate variation drive changes in local abundances, immigration and emigration. In doing so, I will narrow the gap between local and global processes and ultimately link species- and global-level dynamic s.

Funding scheme:

FRIMEDBIO-Fri prosj.st. med.,helse,biol

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